Reverse Flow Under Gravel Filtration

Dear Aquaworld,

I'm sure you guys get all kinds of strange questions, but I'm new and green. I don't know what is a strange question and what is not. I want to set up my first tank.
Someone told me about a new idea that involves using a canister filter for the primary filtration,
and returning the filtered water to the tank UNDER the gravel, to blow detritus and waste OUT of
the sand/gravel bottom into the water, where it will be removed by the canister filter. This sounds weird, and I don't know what to make of it. Nor can I imagine how to set up
such a filtration system. I'm hoping you can tell me whether or not this idea is hogwash,
and if it's not, offer some advice/insight.

Thanks for your time and help!

Respectfully,

Bob Wallen
Temple Terrace, Florida, USA

Dear Bob,

The system you are describing is often referred to as reverse flow under gravel (UG) filtration. Some people use a power head with a pre-filter attached to the intake and then pump the water under
the UG filter plate. Under gravel filtration is no longer recommended whether it is normal or
reverse flow, as detritus (fish waste, and other decaying material) gets trapped under the plate. Over time the trapped detritus will bring down the water quality, and the only way to remove it is
to take the UG filter plate out.

The easiest way to filter an aquarium today is to use a hang on
the tank power filter. I recommend sand as a substrate, as it helps keep detritus on top of the bed
so the filter can remove it. If you already have a canister filter, make sure you keep up on the
maintenance, as people with canister filters often don't clean them as often as they should.